1. Field of the Invention
The present invention relates to an endoscope cover-sheathed endoscope system having an endoscope cover for use in sheathing an endoscope.
2. Description of the Related Art
In recent years, endoscopes have been widely adopted in the field of medicine. When an endoscope designed for medical use is employed to conduct an endoscopic examination, the endoscope must be thoroughly cleaned and disinfected before examination.
An air/water supply channel and a forceps channel are usually formed in an endoscope, which poses a drawback that it takes much time to thoroughly clean or sterilize these channels and their insides alike after use. Unless sterilization is performed thoroughly, satisfactory effects are not expected. The sterilization cannot help therefore being continued for a prolonged period of time. This deteriorates the use efficiency of an endoscope. Besides, the work of sterilization is a nuisance.
In consideration of the foregoing drawbacks, an endoscope cover-sheathed endoscope system has been proposed in, for example, Japanese Patent Publication No. 1990-54734 and U.S. Pat. Nos. 3,162.190, 5,050,585 and 4,646,722, wherein an endoscope is used with its body sheathed with an endoscope cover, the endoscope cover alone is disposed of after every use so that the endoscope body will not become dirty, and thus either cleaning or sterilization need not be done.
To be more specific, the insertional part of an endoscope-cover coverable endoscope to be sheathed with an endoscope cover is cleaned or sterilized beforehand, sheathed with the endoscope cover, and then inserted into a patient's body cavity to carry out examination or treatment. Thus, the endoscope will not touch the patient's body cavity directly. After use, the endoscope cover used to shield the endoscope body is removed and disposed of. Thus, since an endoscope cover is disposable for each patient, an endoscope need not be cleaned or disinfected but handled very conveniently.
The aforesaid endoscope cover usually consists of multiple cover members; such as, an insertional part cover, a operational part cover, and an universal cord cover linked with one another in that order from the distal end of the endoscope cover. In this arrangement, a conventional endoscope cover-sheathed endoscope system has not been designed to take care of a junction between each pair of adjoining cover members. An endoscope is therefore exposed to the outside at a border between adjoining cover members.
In the above case, since the endoscope is not sterilized before use, bacteria may adhere to the endoscope. If gloves or bare fingers touch the bared portion, bacteria adhere to the gloves or bare fingers. The bacteria may eventually adhere to the surface of an endoscope cover via the gloves or bare fingers.
To avoid the above incident, a user must handle an endoscope with extreme care so as not to touch an bared portion of the endoscope. Alternatively, a sterilized endoscope must be used with it sheathed with an endoscope cover.
In the aforesaid endoscope cover, a conventional cover skin for shielding the insertional part of an endoscope is realized with a thin membranous member made of a soft material. For example, Japanese Patent Publication No. 1990-54734 has proposed an endoscope cover consisting of a rigid cover fitted into a distal structure of an endoscope so as to shield the distal structure and a flexible cylindrical shielding member for shielding an insertional part formed at the proximal end of the rigid cover.
The foregoing endoscope cover-sheathed endoscope has been utilized for various applications. For observation of an abdominal cavity, for example, a distally-bending rigid scope sheathed with an endoscope cover is inserted into the abdominal cavity via a trocar or other rigid sheath punctured at the patient's abdomen. In this observation, generally, air is supplied to inflate the abdominal cavity for clear visualization, and then a field of view is focused. The air supplied to the abdominal cavity must not leak out of a gap between the rigid sheath and endoscope cover. An airtight packing is mounted in the rigid sheath to block the gap between the rigid sheath and endoscope cover, thus ensuring airtightness.
A soft endoscope covert has been used to sheath a conventional laparoscope. When the laparoscope is inserted into a rigid sheath or operated with it inserted into a rigid sheath, if an attempt is made to insert, remove, or manipulate the laparoscope forcibly, the endoscope cover wrinkles because a frictional force is exerted in an area in which the cover skin of the endoscope cover rubs against the airtight packing. If the laparoscope is handled further Forcibly, the endoscope cover may be pierced or damaged. To avoid these incidents, a laparoscope must be inserted into or removed from a rigid sheath, or manipulated very carefully.